[Keeper of Dol Guldur]

Yes, the Edain were the first of men, folks like Barahir, Beren, and that bunch of fellows who got involved with the wars between the Elves and Morgoth.

The Dale-men (and surrounding areas like Laketown), and the Rohirrim were descended from a long line from those original men, but none were more closely descended than the Beornings.

Likewise, I think the Dunlanders were descended, perhaps from the traitors, the dark Edain who stabbed the Eldar and the Edain in the back, the 'original easterlings' (who weren't really from that far east). After the remnants fled (if any did ... I can't really remember) from the lost battle, they may have settled in the lands west of the Gap of Rohan.

As for the folks of Bree, while they may have been related to the Dunlanders, they never left Bree, never were involved in any treachery or anything, and never fell into shadows, so to speak. They're just, Bree-folk. They always have been.

The Edain, the special ones who helped elves out, obviously were taken to Numenor and became the Dunedain.